Tailstock construction for lathes



Dec. 1, Y LE B ND 2,062,790

TAILSTOCK CONSTRUCTION FOR LATHES Filed May 1;, 1955 2 Sheets-Sheet 23 626 27 .22 24.-

Patented Dec. 1, 1936 UNITED STATES "PATENT oF-Fic-e TAILSTOCKCONSTRUCTION FOR-LAIHES Richard K. Le Blond, Cincinnati, Ohio, ,assignorto The R. K. Le Blond Machine Tool Company, Cincinnati, Ohio, acorporation of Delaware Application May 13, 1935, Serial No., 21,209zCiaims. (cite-31) a'relatively large amount of axial travel while at vthe same time providing maximum bearing contact for the spindle in thetailstock housing during the entire length of such travel.

Another object of my invention is to provide a tailstock with a spindlehaving a large unobstructed hole passing through its entire lengththrough which bar stock or the like may be in- 16 serted for machiningoperations.

Still another object is the provision of a novel actuating meanscomprising a worm carried on a shaft not coaxial with the center of thetailstockspindle which operates in a suitable rack cut in the tailstockspindle, such construction permitting more convenient location of theactuating handwheel and also allowing the tailstock spindle to pass thehandwheel in its withdrawn position.

A further object is the provision of an actuat-- ing means or tailstockwhich is efiectively selflocking as I shall hereinafter describe.

A further object is to provide a suitable spindle nose constructionwhich is adapted for the holding of centers, drills, reamers, etc.;while allow- I ing a large unobstructed hole through the entire lengthof the spindle when these devices are removed.

Another object is to so construct the actuating handwheel as to allow'asuitable bar or rod to be inserted between the spokes in a large numberof difierent positions for the purpose of applying heavy pressure to thetailstock spindle for drilling, reaming, or the like, the constructionbeing such as to allow easy insertion and removal of the bar and toprevent all possibility of slippage and subsequent injury to theoperator.

These and other objects of my invention which will be set forthhereinafter or will be clear to one skilled in the art upon readingthese specifications I accomplish by that certain construction andarrangement of parts of which I shall now set forth an exemplaryembodiment. Reference is made to the accompanying drawings in which:

' Figure 1 is a front elevation of the improved tailstock showing thenovel actuating means for the spindle and showing the unobstructed hole56 passing completely through the spindle.

Figure 2 is a plan view further illustrating the actuating means ofFigure 1.

Figure 3 is a fragmentary elevation of the nose.

portion of the tailstock. I

Figure 4 is a section on line 4-4 of Figure 3 5 showing one type ofspindle bore.

Figure 5 is a section on line 5-5 of Figure 6 showing another type ofspindle bore and tool holding sleeve.

Figure 6 is an end view of the spindle shown 10 in Figure 5.

Figure 7 is .a. face view of the actuating handwheel. I I

Figure-8 is a section of the handwheel on line 8-8 of- Figure 7. 15

The main housing of the tailstock is shown as carried on a base piece 2which piece in turn rests in the ways 3 of the bed 4 of the lathe.Suitable clamping screws 5 and clamps (not shown) adjustably secure themembers I and 2 20 to the bed 4 as is usual for tailstocks.

A spindle 6 is mounted in the upper part of the main housing i and isdisposed in parallelism with the ways 3 of the bed 5 for alignment withthe spindle of the headstock (not shown). able bearings 1 and 8 areprovided, the bearing 8 toward the headstock end being split at 9 and aclamping means It provided for locking the. spindle 6 in a rigidposition, as is also usual. On the bottom of the spindle 6 is cut a rackII with 30 angular teeth, which rack may extend the entire length of thespindle 6 but is usually not cut in that part of the spindle embraced bybearing 8 when in its fully retracted position. Engaging this rack II isa worm I2 carried, in a pocket I3, 35 of the housing i, on a shaft M.This shaft is angularly disposed relative to the axis of 'the spindle 6Bearings l5 and I 6 in the main body portion I carry the shaft M, whichshaft has attached to the end projecting from the bearing 40 iii anoperating handwheel ll. An anti-friction thrust bearing i8, bearingbetween the shoulder I9 of the worm' l2 and the face 20 of the bore 2|-in the body I, takes the axial thrust imposed upon the worm by thereaction of the spindle.

It can be clearly seen from Figure 2 that the angular relationshipbetween the spindle and shaft M can be such as to allow the spindle tobe retracted until it passes beyond the handwheel l4 and assumes such aposition as that illustrated at 6a. By such an arrangement very longtravel can be imparted to the tailstock spindle and also full bearingcontact can be main tained at all times in bearing 1 even when thespindle is very greatly extended. "A further ad- Suit- 2c operator'sside of the machine where it 'is more accessible and convenient to theoperator. is to be also noted that the handwheel may be located at theleft hand end portion of the tailstock shown in Figures 1 and 2 withoutdeparting from the spirit of my invention. While it is not essential, itis usual in this construction so to arrange the rack II and worm l2 thatthe handwheel I! will be revolved counter-clockwise when the spindle 6is extended outwardly to the left, so as to keep the teeth of therack Iiat as nearly a right angle to the axis of the spindle 6 as possible.Thus I prevent the worm l2 being driven by the rack II as might be thecaseif the rack teeth were more nearly parallel to the axis of thespindle. In. this way. substantially a self-locking taflstock spindleactuating means is provided; and while it will be usual when turning tolock the tailstock spindle by the means described, yet when reamers,drills or the like are to be used in the tailstock, the tailstockspindle may be advanced under great pressure without encountering heavyback pressure on the actuating device.

By means of the arrangement above described I can provide a noveltailstock spindle. as illustrated in Figures 3, 4, 5 and 6, having anunobstructed hole or bore 22 passing axially through its entire length.In Figures 3 and 4 is illustrated one format such spindle having theusual tapered bore 23 and a large straight bore 23. Anarrangement,consisting of a boss having a hole 25 and slots 26, maybe formedintegral with the spindle 6 so as to provide holding means for the tangof the usual taper shanks of drills, reamers, or the like. A taperedportion 21 is formed in the boss so as to guide a knock-out rod throughthe hole 25 for the purpose of 'removing the center or drills andreamers. A key 23 secured in the housing I of the tailstock slidablyengages a longitudinal slot 29 in the spindie 6 so as to preventrotation of the spindle.

Another form of tailstock spindle is that shown,

in Figures 5 and 6 in which the bore 22 has the tapered section 30 andthe large diameter straight section 3|. An adaptor bushing 32 fitting inthe tapered portion 30 has lugs 33 integral therewith and locateddiametrically opposite each.

other on its larger outer end, which lugs, in turn, fit in matingrecesses 33 in the end of the spindle 6 so as to prevent rotation of thebushing 32 in the. spindle. A, hole 35 and slots 33 are prothe tang ofdrills, reamers, or the like. holding said tools positively againstrotation when work is being done therewith. It can be clearly seen thatwhen the bushing piece 32 is removed a much larger unobstructed hole isthus provided through the tailstock spindle.

The handwheel ll provided for actuating the worm and rack mechanismalready described is of novel construction in that the arrangement ofthe rim 31 and spokes33 are such as to allow a bar or rod 33 to beinserted radially in a large number of diiferent positions without thedanger of the rod slipping and causing injury to the operator. This Iaccomplish by ofisetting the rim 3'! axially from the hub 33sufliciently to allow a suitable bar'33 to pass between the face ll ofthe 'hub and .the edge 32 of the rim 31. It is also important to havethe middle portions 43 of the spokes substantially parallel with theaxis of rotation of the handwheel Il so as to form a bearing for the rodor bar 33 which will not tend to cause 'thebar to slip. Figure '7 showstwo of the possible positions of a bar 33 when in use to increasetheleverage of the handwheel l'l. Having thus described my invention,what I claim as newand desire to secure by Letters,

- Patent, is:--

1. A tailstock comprising a housing, a spindle mounted for axialmovement in said housing, a rack on said spindle, a worm operativelyengaging said rack, a worm shaft joumaled in said housing in a pluralityof bearings, the axis of said worm shaft being angularly disposedrelative to the axis of said spindle, said worm being mounted on saidshaft intermediate some of said bearings, and a handwheel connected tosaid worm shaft for. rotating the same.

2. In a tailstock, the combination of a housing, a spindle having an;unobstructed ,axial bore through its entire length, a rack on saidspindle,

a worm operatively engaging said rack, a worm shaft rotatively mountedin a plurality of bearings in said housing, said worm being mounted onsaid shaft intermediate some and adjacent at least one of said bearings,a handwheel connected to said worm shaft for rotating the same, the axisof the worm shaft and handwheel being angularly positioned relative tothe axis of the spindle so as to allow passage of said'spindle beyondsaid handwheel when said spindle is in its longitudinally retractedposition.

RICHARD K. LE 13mm).

